Simulation-Driven Design and Synthesis of DES-PDMS Membranes for Enhanced Ethanol Pervaporation

Efficient separation of ethanol from water is a critical challenge in the biofuel industry, where traditional methods often fall short in terms of energy efficiency and selectivity. To address this, we explore the potential of novel deep eutectic solvents (DESs) to enhance the performance of pervaporation membranes. Using the Conductor-like Screening Model for Realistic Solvents (COSMO-RS), we identified a promising menthol/thymol based DES with exceptional hydrogen bonding and selectivity properties. Incorporating this DES into poly(dimethylsiloxane) (PDMS) membranes led to significant improvements in separation efficiency. Our DES-PDMS membranes, particularly with a 1:6 molar ratio and 5-10% DES loadings, demonstrated outstanding performance at 60 °C, achieving total fluxes of 0.47 and 0.36 kg m^-2 h^-1, and separation factors of 26 and 33, respectively. These results align well with the COSMO-RS predictions, highlighting the enhanced chemical affinity between the DES and PDMS, which maintains hydrophobicity and reduces water absorption. This study introduces a novel strategy for membrane performance enhancement, offering significant promise for efficient ethanol separation and broader applications in advanced separations.